Chapter 4 Uhf Band 1 Theory Of Operation; Transmitter; Figure 4-1. Transmitter Block Diagram - Motorola HT Series Detailed Service Manual

UHF Band 1 Theory of Operation: Transmitter

Chapter 4 UHF Band 1 Theory of Operation

4.1

Transmitter

From VCO
4.1.1 General
(Refer to Figure
The UHF transmitter contains five basic circuits:
• Power amplifier
• Antenna switch
• Harmonic filter
• Antenna matching network
• Power control integrated circuit (PCIC)
4.1.2 Power Amplifier
The power amplifier consists of two devices:
• 9Z67 LDMOS driver IC (U101)
• PRF1507 LDMOS PA (Q110)
The 9Z67 LDMOS driver IC contains a two-stage amplification with a supply voltage of 7.3 V.
This RF power amplifier is capable of supplying an output power of 0.3 W (pin 6 and 7) with an input
signal of 2 mW (3 dBm) (pin16). The current drain would typically be 160mA while operating in the
frequency range of 403-470MHz.
The PRF1507 LDMOS PA is capable of supplying an output power of 7 W with an input signal of 0.3
W. The current drain would typically be 1300mA while operating in the frequency range of 403-470
MHz. The power output can be varied by changing the biasing voltage.
P C I C
Vcontrol
P A
Driver

Figure 4-1. Transmitter Block Diagram

4-1.)
Vcontrol
Antenna Switch/
PA - F i n a l
Harmonic Filter/
Sta g e
Matching Network
Antenna
Jack
4-1